1. 嘴 (zuǐ): This is the most common way to write "mouth" in Chinese. It refers to the mouth as a physical organ.
2. 口 (kǒu): This character also means "mouth," but it's more abstract and can also mean "opening," "entrance," or "hole." For example, you can use "口" to talk about the mouth of a bottle or a cave.
Therefore, it's important to consider the context when choosing the correct character for "mouth."